Hoarseness or Swallowing Problems -- Difficulty swallowing is most commonly associated with esophageal or throat cancer, but can also be one of the first signs of lung cancer. A hoarse voice or feeling of something pressuring the throat can be an early indicator of thyroid cancer, according to Care.com.

Testicular Lump or Swelling -- The lumps that point to testicular cancer are nearly always painless. It's also common for a testicle to be enlarged or swollen without any particular lump to point to, according to Care.com.

Upset Stomach -- Bellyaches tipped off a number of people to liver tumors, and stomach cramps or frequent upset stomachs may indicate colorectal cancer.

Unexplained Weight Loss -- If you're shedding weight and haven't made any changes to your diet or exercise plans, it could be colon and other digestive cancers. It's also a sign of cancer that's spread to the liver, according to Care.com.

Wheezing or Shortness of Breath -- One of the first signs lung cancer patients remember is the inability to catch their breath. Thyroid cancer can also cause breathing problems.

Chronic "Acid Stomach" or Feeling Full After a Small Meal -- The most common early sign of stomach cancer is pain in the upper or middle abdomen that feels like gas or heartburn.

Bowel Problems -- Constipation, diarrhea and changes in stools can all be signs of cancer. The key is whether it goes on for more than a few days without a clear cause.

Difficulty Urinating or Changes in Flow -- In men, the most common early sign of prostate cancer is a feeling of not being able to start urinating once you're set to go. Many men also report having a hard time stopping the flow of urine.

Erection Problems -- As prostate cancer progresses, a common sign is difficulty getting or sustaining an erection.

Weakness and Fatigue -- General weakness and fatigue could mean a number of things, but when combined with other symptoms could mean cancer or other diseases.

Frequent Fevers or Infections -- Frequent high temperatures can be a sign of leukemia, which causes bone marrow to produce abnormal white blood cells and sap the body's infection-fighting abilities.

Changes in Fingernails -- A brown or black streak or dot under a fingernail can mean skin cancer, while enlarged ends of the fingers with curved nails can be a sign of lung cancer. Pale or white nails could mean your liver's not functioning properly, perhaps due to cancer.